Approximately 50% of all cardiovascular disease deaths are sudden and unexpected. The incidence of sudden death in the United States ranges from 200,000 to 450,000 annually. The implantable cardioverter defibrillator (ICD) is used in patients at risk for ventricular arrhythmias and sudden death. Implant rates have increased ten-fold 1990-2008. Many ICD patients experience depression and anxiety (up to 38%), and reduced quality of life (QOL). Several studies have demonstrated associations between emotion and autonomic function, arrhythmias, and cardiac events; however, thus far studies have not been able to demonstrate the mechanism by which emotion and arrhythmias are connected. Autonomic function is one mechanism that is hypothesized to link emotion to arrhythmias. Markers of diminished parasympathetic activity are associated with both ventricular arrhythmias and sudden death; and with depression and anxiety. Patients with ICDs are particularly susceptible to emotion-triggered arrhythmias, sudden death and ICD shocks. Thus, ICD patients may directly benefit from a treatment that improves mood, autonomic functioning, and arrhythmias. Cognitive behavior therapy (CBT), which focuses on symptom reduction of negative emotions, has been the standard non- pharmacologic treatment of depression and anxiety disorders. CBT has improved depression symptoms and autonomic functioning in ICD patients, but has not reduced the frequency of arrhythmias. Previous studies may have been too narrowly focused on the reduction of negative emotions. In contrast, positive emotions are associated with better physical health, QOL, longevity; and reduced symptomatology, and mortality risk. Studies indicate that positive emotion may influence autonomic function by heightened parasympathetic activity and accelerating cardiovascular recovery following a negative emotion or stressor. Quality of Life Therapy (QOLT) combines CBT and positive psychology techniques and has been empirically validated to improve positive emotion, QOL, and to reduce negative emotion. A paradigm shift toward enhancing positive emotions may provide a beneficial effect on reducing arrhythmia burden. The proposed study will: 1) examine the feasibility and acceptability of a 3-month positive-emotion focused therapy (QOLT) modified specifically for ICD patients; and 2) obtain estimates of effect size for QOLT compared to Heart Healthy Education on the changes in arrhythmia frequency and biomarkers of autonomic function, as well as changes in emotion, mood, and well-being across time (baseline, 3 & 9-months). This study will use a RCT design with a Heart Healthy Education (HHE) contact control condition. Innovative aspects of this trial include: (1) the focus on positive emotion to improve mood, autonomic function and reduce arrhythmias, and (2) the use of linear and nonlinear measurements of heart rate variability and heart rate turbulence. A subsequent larger trial (e.g., R01) will allow rigorous examination of this non-invasive, non-pharmacological intervention to reduce frequencies of arrhythmias in ICD patients.